The purpose of this project is to study the chemical and physical characteristics and the biosynthesis of cartilage proteoglycans. Topics of present interest are: 1) chemistry of proteoglycans isolated from bovine hyaline cartilages and from the Swarm rat chondrosarcoma; 2) mechanisms of proteoglycan aggregation; 3) biosynthesis of the protein core of proteoglycans isolated from chick limb bud chondrocytes grown in vitro; 4) metabolism of proteoglycans during chondrogenic and osteogenic phases induced by implants of demineralized bone matrix in rats; 5) physical chemical analyses of proteoglycans and proteoglycan derivatives; 6) interactions of proteoglycans with type II collagen.